System for storing water

ABSTRACT

A system for storing water in or under a concrete slab of the type in which one or more void forming elements are used to form one or more voids in the concrete slab. The system comprises one or more water storage means, such as pipes ( 12, 14, 26, 18  and  20 ) positioned in the one or more void forming elements ( 10 ) and at least one port ( 26 ) for supplying water to the one or more water storage means. The void forming elements may be boxes.

FIELD OF THE INVENTION

The present invention relates to a system for storing water. In another aspect, the present invention relates to a concrete slab used in the construction of a building. In a further aspect, the present invention relates to a method for forming a system for storing water. In yet a further aspect, the present invention relates to a method for forming a concrete slab.

BACKGROUND OF THE INVENTION

Drought conditions frequently extend across large areas of the Australian continent. This can lead to restrictions in the supply of water to even capital cities which, in turn, can result in water supply authorities imposing quite strict restrictions on the use of water.

As a result of recent drought conditions across Australia, it is becoming more commonplace for households to want to obtain a separate store of water that the households can use for purposes such as watering of gardens and washing of cars that are banned from use under harsh water restrictions that apply if using reticulated water from the water supply. The typical solution sought in response to the desire to have a separate store of water involves collecting rainwater from the roof of a building and storing that rainwater in a rainwater tank or a rainwater bladder. Furthermore, a number of local councils are now requiring that all new dwellings include some form of rainwater storage on the premises.

Although rainwater tanks are becoming much more prevalent, rainwater tanks and rainwater bladders occupy a large area, are obtrusive and are prone to damage.

Construction of buildings, such as residential housing and commercial buildings, on building sites that have reactive soils or problem soils, has posed many challenges to the construction industry. As is known to persons skilled in the art, reactive soils undergo significant swelling as their moisture content increases and significant shrinkage as their moisture content decreases. Consequently, reactive soils typically exhibit significant variations in soil height. Therefore, the construction industry faces significant issues in designing and building foundations and slabs for buildings located on reactive soil sites.

One possible solutions that is used to combat the difficulties faced in building on building sites that have reactive soils or problems soils involves use of floating concrete slabs, particularly in residential housing and small commercial buildings. Floating concrete slabs are formed on the soil surface. The floating slab is designed to be very stiff and very strong. If the soil shrinks (for example, during a prolonged dry spell), the soil shrinks away from the concrete slab, particularly around the edges of the slab. Due to the strength of the slab, the slab is strong enough so that any unsupported regions underneath the slab do not break. Similarly, if the soil expands, the slab can shift upwardly with the expanding soil.

Originally, floating slabs were very thick and required exceedingly large amounts of concrete. Consequently, those slabs were also very expensive to construct. In order to address these issues, so-called “waffle raft” slabs were developed. Waffle raft slabs are formed by setting out formwork on the ground, positioning a plurality of void forming elements (typically expanded polystyrene boxes or, on occasions, cardboard boxes) at desired positions, placing appropriate reinforcement material and pouring concrete. The void forming elements reduce the amount of concrete required in the slab and result in the formation of a slab having a plurality of ribs, set out typically in a grid pattern. If the slab could be viewed from underneath, it would resemble the surface of a waffle, hence the name “waffle raft slab”. Such slabs are also called “waffle pod slabs”.

Throughout this specification, the word “comprising” and its grammatical equivalents shall be taken to have an inclusive meaning unless the context of use indicates otherwise.

The applicants does not concede that the prior art discussed in this specification forms part of the common general knowledge in Australia or elsewhere.

BRIEF DESCRIPTION OF THE INVENTION

It is an object of the present invention to overcome or at least ameliorate one or more of the disadvantages of the prior art.

In a first aspect, the present invention provides a system for storing water in or under a concrete slab of the type in which one or more void forming elements are used to form one or more voids in the concrete slab, the system comprising one or more water storage means positioned in the one or more void forming elements and at least one port for supplying water to the one or more water storage means.

In practice, the void forming elements will typically comprise boxes. For convenience, the invention will be described hereinafter with reference to the void forming elements being in the form of boxes. However, it will be appreciated that the present invention encompasses other void forming elements as well.

The system for storing water includes at least one port for supplying water to the one or more water storage means. The at least one port may also be used for extracting or removing water from the system for storing water.

The at least one port is desirably placed into fluid communication with the roof, and guttering and/or down pipe(s) of the building. In this fashion, the water storage system of the present invention can collect rainwater from the roof of the building.

The system may also be provided with one or more water outlets for removing water therefrom. The one or more water outlets may be in the form of one or more sumps. The one or more water outlets may be in the form of one or more valves or taps.

The water storage system may be provided with one or more filters, first flush diverters or other bypass arrangements. These products are designed to ensure that the collected rain water entering the water storage system is relatively clean. Other products that can be used to improve the quality of the water entering the water storage system may also be used.

The one or more water storage means may comprise one or more pipes.

The water storage system may include at least one manifold that is connected to at least one down pipe from the roof or guttering of the building. The at least one manifold may include one or more outlets that are connected to one or more of the water storage means. The at least one manifold may include two or more outlets that are connected to the water storage means.

In one embodiment, the concrete slab is provided with a plurality of void forming elements that are spaced from each other, two or more of the void forming elements having water storage means located therein, and the system further includes conduit means interconnecting one of the water storage means to another of the water storage means.

In some embodiments, the water storage means includes a plurality of pipe modules, each module being positioned in a void forming element, and one or more of the pipe modules being connected to and into fluid communication with another of the pipe modules. In other embodiments, the water storage means may comprise one or more tanks or one or more pipes.

The void forming elements may be in the form of boxes made from expanded polystyrene. The void forming elements may also be in the form of cardboard boxes.

In a second aspect, the present invention provides a concrete slab for a building in which one or more void forming elements form one or more voids in the concrete slab, characterized in that the slab includes one or more water storage means positioned in the one or more void forming elements.

The concrete slab of the second aspect of the present invention may include other features as described with reference to embodiment of the first aspect of the present invention.

In a third aspect, the present invention provides a method for forming a concrete slab for a building comprising the steps of placing one or more void forming elements at required locations, placing reinforcement as required and pouring concrete to cover the void forming elements and reinforcement, wherein one or more water storage means are positioned in the void forming elements.

In a fourth aspect, the present invention provides a method for forming a water storage system comprising the steps of placing one or more void forming elements at required locations, placing reinforcement as required and pouring concrete to cover the void forming elements and reinforcement, wherein one or more water storage means are positioned in the void forming elements.

The present invention provides a water storage system that is positioned out of sight and therefore does not occupy space that the building owner may otherwise wish to utilize for other uses. The water storage system is effectively positioned underneath the building slab and is therefore protected against damage by the building slab. As the water storage means, such as the water storage pipes, is positioned in the boxes, if there is expansion of the ground underneath the slab, the pipes have a degree of movement available to them that allows the pipes to move upwardly. This upward movement of the pipes is accommodated by the compressibility of the material, such as expanded polystyrene or cardboard, from which the boxes are made.

In some embodiments, the void forming elements are in the form of boxes and the boxes may be pre-assembled with the water storage means positioned therein prior to delivery to a building site. In this manner, relatively quick completion of the building slab and the water storage system can be achieved.

According to a fifth aspect, the present invention provides a box for use in the construction of waffle slabs, characterized in that the box includes a water storage means positioned below an upper surface of the box.

In a further embodiment, the water storage system may be mounted inside a wall of the structure or building wall attached to the wall of structure or building. Desirably, the water storage means is positioned inside a box. The box may be made from expanded polystyrene. The box may be mounted to the wall. In this embodiment, the box is desirably able to be rendered, painted or clad in an aesthetically pleasing finish.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partly in cross-section, showing part of a water storage system in accordance with an embodiment of the present invention;

FIG. 1A is a perspective view, partly in cross-section, of a modified water storage system similar to that as shown in FIG. 1;

FIG. 2 is a plan view of the part of the water storage system shown in FIG. 1;

FIG. 3 is a plan view showing a water storage system in accordance with an embodiment of the present invention;

FIG. 4 is a plan view of another water storage system in accordance with another embodiment of the present invention;

FIG. 5 is an end of view showing a water storage pipe located within a box;

FIG. 6 is an end view of another embodiment of a water storage pipe located within a box;

FIG. 7 shows an end view, partly in cross-section, of a concrete slab incorporating a water storage system in accordance with an embodiment of the present invention;

FIG. 8 shows a side view of an arrangement to supply collected rainwater to a water storage system in accordance with the present invention; and

FIG. 9 shows an end view of the arrangement shown in FIG. 8.

DETAILED DESCRIPTION OF THE DRAWINGS

It will be understood that the drawings have been provided for the purposes of illustrating preferred embodiments of the present invention. Therefore, the present invention should not be considered to be limited to the features as shown in the attached drawings.

Throughout the attached drawings, the direction of water flow is shown by arrows.

FIGS. 1 and 2 show a perspective view and a plan view, respectively, of a box 10 suitable for use in the present invention. The box 10 may de similar to a product sold under the trade name “waffle pod”. The box 10 is suitably a hollow box having side walls 11, 13, end walls 15, 17 and a top wall. The box 10 may have walls that are made from expanded polystyrene.

The box 10 is fitted with a plurality of pipes 12, 14, 16, 18 and 20. These pipes are sequentially connected by means of connectors 22. An elbow joint 24, positioned outside the rear wall of the box 10 and connected to an inlet region of pipe 12 is connected to a vertical riser pipe 26, such as a downpipe.

The end 28 of pipe 20 extends out through the front wall of the box 10. End 28 provides an outlet.

In assembling the pipe layout as shown in FIG. 1, the pipes are placed in the expanded polystyrene box 10 and held in place by internal partitions. The assembled box shown in FIG. 1 is subsequently placed on the ground within the formwork used to make a concrete slab. Appropriate reinforcing is laid around and over the box 10 and concrete is subsequently poured to form the slab.

The boxes shown in FIGS. 1 and 2 may have dimensions of approximately 1080 mm length by 1080 mm width by 300 mm depth. However, other dimensions can also be used. The preferred dimensions of the pipes used within each box may include 160 mm diameter by 655 mm length. However, other dimensions can also be used.

The boxes shown in FIGS. 1 and 2 have an open bottom. However, it will also be understood that the boxes may have an open side that may be placed adjacent to the exterior side of the wall. Further, the pipe layout within the boxes may be fitted on site or they may be fitted at a factory prior to delivery to the construction site.

FIG. 1A shows a box that is generally similar to the box shown in FIG. 1 (and like parts in common between FIG. 1 and FIG. 1A are denoted by like reference numerals). The box of FIG. 1A differs in that it includes openings 25, 27 in the side walls thereof to allow for a straight pipe to pass through those openings. This may be required to avoid plumbing or electrical fittings in the slab or in the box.

FIG. 3 shows a plurality of boxes 10 that are configured with pipes as shown in FIGS. 1 and 2. As can be seen from FIG. 3, the outlet of a pipe on one box is connected to an inlet of a pipe from another box, for example, by connecting pipes or conduits 30. A larger connecting conduit 32 is also provided.

In the arrangement shown in FIG. 3, the water storage system includes the pipes located within the plurality of boxes 10. The water system also includes an inlet port 36 and an outlet port 38. The inlet port 36 may be connected to a down pipe so that rainwater collected from the roof of a building can be supplied to the water storage system. The outlet port 38 may form part of a sump. Alternatively, the outlet port 38 may be in the form of a valve or tap, or it may be connected to an outlet pump so that water contained in the water storage system can be pumped therefrom.

It will be appreciated that the arrangement of boxes shown in FIG. 3 will become covered by concrete during the construction of a concrete slab used in a building, such as a domestic dwelling. The extent of the concrete slab may be as shown with reference to the dotted outline 40 shown in FIG. 3.

FIG. 4 shows a plan view of an alternative water storage system in accordance with another embodiment of the present invention. In FIG. 4, the water storage system includes boxes 50, 52 and 54 that have pipes that are connected at connections 56 and 58. An outlet 60 is provided for the storage pipes in boxes 50, 52 and 54. Similarly, boxes 62, 64 and 66 have storage pipes that are connected via connection conduits 68 and 70. The pipe system contained in boxes 62, 64 and 66 have a separate water outlet 72.

Box 50 includes a water inlet 74. Box 62 includes a water inlet 76. Water inlets 74 and 76 are connected to a manifold 78 that, in turn, is connected to down pipes via vertical pipes and 80, 82. Therefore, manifold 78 collects water from two down pipes and supplies water to the pipe systems contained within the boxes. The manifold 78 may suitably be positioned externally to the slab and externally to a wall of the building.

The pipes that are used in the piping layout in the boxes shown in FIGS. 1 to 4 are suitably PVC pipes. However, other material may be used to make the pipes. The pipes may have any desirable dimensions. The manifold shown in FIG. 4 is also suitably made from a PVC pipe. The connection points between the manifold and the water inlets of the piping system within the boxes may be a T-shaped joint with a screw cap inspection point.

FIG. 5 shows one possible arrangement for the exit point where a pipe exits a box, for example where pipe 28 exits box 10 as shown in FIG. 1. In FIG. 5, the exit pipe 90 extends through an opening in the side or in the wall of the box. The opening is formed by having part of the end wall formed in two pieces 92, 94. Piece 94 includes a cradle 96 on which the periphery of the pipe 90 rests. Similarly, piece 92 includes a cradle 98 that rests on the periphery of the pipe. The blocks shown in FIG. 5 may have typical dimensions of 1080 mm×1080 mm and a height of 300 mm. The upper peace may have a height of 175 mm in the long peace may have a height of 125 mm. The payment of the entry and exit ports maybe 180 mm. The box may be a solid construction of expanded polystyrene with a 180 mm groove formed therein for the pipes to be cradled in. These dimensions are suitable for use with a pipe of diameter of 160 mm.

FIG. 6 shows an alternative arrangement to that shown in FIG. 5. In FIG. 6, a pipe 100 simply extends through an opening 102 formed in the side wall or end wall 104 of the box.

FIG. 7 shows a cross-sectional view of an interconnection of the pipe systems between two adjacent boxes. In FIG. 7, first box 110 has a pipe outlet 112 and second box 114 has a pipe inlet 116. Interconnecting pipe 118 connects the pipe inlets and outlets together.

Also shown in FIG. 7 is the concrete slab 120. As can be seen, concrete slab 120 surrounds the boxes 110, 114. Further, concrete slab 120 encases the interconnecting pipe 118.

If the ground underneath the slab 120 expands (for example, due to increasing moisture content in the soil), the slab 120 and the boxes 110, 114 are pushed upwardly. If there is any differential expansion of the ground, the differential movement can be accommodated by the pipes compressing the material from which the boxes 110, 114 are made and also by the pipe being able to move within any gaps that exist between the pipe and the box.

In order to construct a slab utilizing the boxes as shown in FIGS. 1 to 4, the boxes are arranged as required. The interconnections between the pipes in adjacent boxes are then completed. The ends of the pipes (i.e., the inlets and the outlets) are then closed and the pipe system is pressure tested to ensure that there are no leaks. Following successful completion of the pressure testing, the concrete slab is poured and a further pressure test conducted to ensure that damage to the piping system did not occur during pouring of the concrete slab. The water storage system may then be completed by connecting the inlets to down pipes of the building and connecting appropriate connections (such as pumps or taps) to the outlets.

FIGS. 8 and 9 showed various views of an interconnection of the piping system contained in the boxes and slab to a down pipe. In FIG. 8, the pipe system includes a water inlet 150 that extends through a wall 151 of the building. This is connected via connecting flange 152 and elbow 154 which, in turn, connects to an S bend arrangement 156. A down pipe 158 is connected to the S bend arrangement 156. The upper end of the down pipe is connected to the guttering system of a building in accordance with known techniques.

The down pipe 158 may include a first coarse filter 160, a second fine filter 162 and a finer still filter 164. This ensures that particulate material, such as dirt, leaves and the like, are filtered from the water before it enters the water storage system contained in the boxes. The filters 160, 162 and 164 may be removable for cleaning.

The water storage system of the present invention provides a water storage system that does not undesirably occupy space. The present inventor has calculated that using pipes having a diameter of 160 mm within the boxes will allow for approximate 20,000 L of storage volume in an average size house. The water storage system may also be placed under driveways or under patios or verandas.

Those skilled in the art will appreciate that the present invention may be susceptible to variations and modifications other than those specifically described. It will be understood that the present invention encompasses all such variations and modifications that fall within its spirit and scope. 

1. A system for storing water in or under a concrete slab of the type in which one or more void forming elements are used to form one or more voids in the concrete slab, the system comprising one or more water storage means positioned in the one or more void forming elements and at least one port for supplying water to the one or more water storage means.
 2. A system as claimed in claim 1 wherein the at least one port is also used for extracting or removing water from the system for storing water.
 3. A system as claimed in claim 1 wherein the at least one port is placed into fluid communication with the roof, and guttering and/or down pipe(s) of a building.
 4. A system as claimed in claim 1 wherein the system is further provided with one or more water outlets for removing water therefrom.
 5. A system as claimed in claim 4 wherein the one or more water outlets comprise one or more sumps or one or more valves or taps.
 6. A system as claimed in claim 1 wherein the one or more water storage means comprise one or more pipes.
 7. A system as claimed in claim 1 further comprising at least one manifold that is connected to at least one down pipe from the roof or guttering of the building.
 8. A system as claimed in claim 7 wherein the least one manifold includes one or more outlets that are connected to one or more of the water storage means.
 9. A system as claimed in claim 1 wherein the concrete slab is provided with a plurality of void forming elements that are spaced from each other, two or more of the void forming elements having water storage means located therein, and the system further includes conduit means interconnecting one of the water storage means to another water storage means.
 10. A system as claimed in claim 1 wherein the water storage means includes a plurality of pipe modules, each module being positioned in a void forming element, and one or more of the pipe modules being connected to and in fluid communication with another of the pipe modules.
 11. A system as claimed in claim 1 wherein the void forming elements comprise boxes made from expanded polystyrene or cardboard boxes.
 12. A system as claimed in claim 1 wherein the water storage system is provided with one or more filters or first flush diverters.
 13. A concrete slab for a building in which one or more void forming elements form one or more voids in the concrete slab, characterized in that the slab includes one or more water storage means positioned within the one or more void forming elements.
 14. A method for forming a concrete slab for a building comprising the steps of placing one or more void forming elements at required locations, placing reinforcement as required and pouring concrete to cover the void forming elements and reinforcement, wherein one or more water storage means are positioned in the void forming elements.
 15. A method for forming a water storage system comprising the steps of placing one or more void forming elements at required locations, placing reinforcement as required and pouring concrete to cover the void forming elements and reinforcement, wherein one or more water storage means are positioned in the void forming elements.
 16. A box for use in the construction of waffle slabs, characterized in that the box includes a water storage means positioned below an upper surface of the box.
 17. A box characterized in that the box includes a water storage means positioned therein, the box being adapted to be mounted inside a wall or to a wall of a structure or building. 